Various types of machinery are subject to vibration that can loosen nuts and bolts. Lock wire has long been used as protection to resist such loosening. Lock wire secures two or more elements together so that the loosening of one element is counteracted by the tensioned wire running through the elements. Most often in a lock wire configuration, two wire strands are wrapped together and then separated such that one strand goes through the bolt or nut head and the other strand goes around the bolt or nut head; the rejoined ends are twisted together, again, on the exiting side of the nut or bolt and so on. Once the wire strands have been inserted through and around all of the nuts or bolts in a particular grouping, the remaining free ends of the wire strands are secured by twisting the terminated ends of the wire strands together.
In large part in the area of machinery vibration, the lock wire method of grouping bolts together has been replaced with steel cable (also referred to as safety cable). Steel cable is made from an assembly of steel wire laid (or twisted) into a helix to produce a strong resilient material. Notwithstanding the strength of steel cable, the termination of a steel cable often results in ends which easily fray. Further, the resultant resiliency of the steel cable makes it difficult to secure the terminated ends by twisting the steel cable ends together. As such, the terminated ends of steel cable passed through holes in a series of nuts or bolts subject to operational vibration is usually secured by a ferrule crimped onto the free end of the cable to secure the cable to the assembly.
In this arrangement, it is often necessary to obtain a predetermined tension on the steel cable looped through the holes in a grouping of nuts and bolts before securing the free end of the steel cable with a ferrule and terminating the excess safety cable. Prior art devices use a pocket into which the ferrule sits where the crimping occurs. This arrangement often requires twisting or other manipulation by the operator to remove the device from the crimped cable-bolt assembly. This movement often compromises the pre-set tension limit on the crimped cable-bolt assembly. It is an object of the present invention to provide a device that allows tensioning of the steel cable to a predetermined limit, ferrule crimping, steel cable free end termination and ejection of the device from the crimped steel cable secured grouping of nuts or bolts without compromising the pre-set tension of the safety cable.